Hazard Working around helicopters
Knowledge and understanding
|Working around helicopters||
Understand all associated hazard knowledge
Helicopters may also be used in emergency situations because of their ability to reach inaccessible areas, travel at speed and to make use of specialist equipment they carry, such as thermal imaging equipment. Helicopters may also be deployed to the scene of an incident by other organisations, such as the police or the media.
The hazards of working around helicopters, in addition to those found on fixed-wing aircraft, may include:
- Moving main and tail rotor blades
- Suspended loads
- Static electricity
- Automatically deployable emergency locator transmitters (ADELTs)
- Water actuated devices
Moving rotor blades
Consideration should be given to the hazards presented by moving rotor blades. Stationary helicopters may have rotor blades still in motion, although this may not be evident, creating hazards to personnel who need to work in or around a helicopter.
On some helicopters, if the rotors are running at a reduced speed, the rotor blades may drop; this is known as blade sailing. This phenomenon should be considered if it is necessary to work near to the helicopter.
If a helicopter has been involved in an incident, its rotor blades may have stored kinetic energy; this could be released, resulting in the rotor blades restarting to move.
Rotor downwash occurs when a helicopter hovers in close proximity to the ground surface. Downwash may be hazardous for up to 70m from the helicopter, with hazards including:
- Damage to vehicles, objects or equipment
- Harm to people, including casualties
- Displacement of people or objects
- Ground or water disturbance
- Unsecured items becoming projectile hazards
- The spread of contaminants at a hazardous materials incident
- Cross-contamination or destruction of evidence
- Reignition or intensification of a fire
Helicopters may use either slings or nets to transport equipment, or carry water in containers when ‘water bombing’ is required. There may be a hazard of impact injuries from suspended loads, especially if personnel and helicopters are working in close proximity. If a load is jettisoned or falls from a helicopter, the impact may injure people or damage objects on the ground.
Helicopters that carry loads normally have an earthing line to discharge static build up. Personnel need to be aware that any load carried under a helicopter has the potential for the build-up of static electricity.
Water actuated devices
Water actuated devices, such as buoyancy bags or inflation packs, may be fitted to helicopters that operate over water to help them stay afloat in the event of ditching. Devices are automatically deployed when immersed in water;. they are usually marked with a warning sign.
Devices may present a hazard if accidental or unplanned actuation occurs, for example if they are subjected to water or foam.
Automatically deployable emergency locator transmitters
Helicopters that operate over water may be fitted with automatically deployable emergency locator transmitters (ADELTs). When released from the helicopter, the transmitter sends a continuous signal to allow responding searching teams to trace it.
The transmitter is deployed by a release mechanism and is automatically ejected away from the helicopter. Accidentally activating an ADELT may create projectile hazards at high speeds and for a distance of approximately 10m.
Most military helicopters have the same hazards as non-military helicopters. The exception is the Boeing Apache attack helicopter, which could be armed with rockets, missiles and guns. They are also equipped with aircrew escape systems, including an explosive canopy ejection system. Any incident involving this type of military helicopter should instead be dealt with using the hazards:
- Control measureRestrict the use of electronic communication devices
- Control measureSite-Specific Risk Information (SSRI): Transport